A method where fluidity of various kinds of cosmetics/perfumeries, pharmaceuticals, agricultural chemicals, adhesives, resins, paints, etc. which are liquid at ambient temperature is controlled so as to process into a form being fit for the purpose of diversified uses is a very important art in industry. In addition, disaster and marine pollution by accident caused by spilled oil are becoming severe social problems but, if oil is able to be solidified, it is possible not only to prevent diffusion of oil but also to easily and efficiently recover it and a gelling treatment of spilled oil is able to be a very effective means for prevention of spilled oil. Moreover, waste edible oil coming out from ordinary households is a cause for the pollution of quality of water and, if the waste oil can be gelled by a simple method and discarded as a solid, its harmful influence on environment is able to be reduced.
With regard to a substance having a function of controlling the fluidity and viscosity of liquid substances as such, there have been known alkaline metal salts of long-chain fatty acids (Patent Document 1: JP-A-55-75493), metal soaps (Patent Document 2: JP-B-59-52196), 12-hydroxystearic acid (Patent Document 3: JP-B-60-44968), condensates of polyhydric alcohols with benzaldehyde (Patent Document 4: JP-A-59-77859), N-acylamino acid amides (Patent Document 5: JP-B-54-33798), etc.
Among them, alkaline metal salts of long-chain fatty acids and metal soaps required much adding amount for gelling or solidifying the liquid organic medium. In addition, with regard to 12-hydroxystearic acid, types of organic medium being able to be solidified are little and gelling ability thereof is low as well and, therefore, the resulting gel has weak strength, is fragile and is apt to be crumbled whereupon it is insufficient in terms of stability of the gel around ambient temperature. On the other hand, although condensates of polyhydric alcohols with benzaldehyde represented by dibenzylidene sorbitol are able to make many organic media into gel, there is a restriction in the joint use with a low-boiling substance or a substance which is not so resistant to heat because their dissolving temperature is high. In addition, there is a disadvantage that the acetal moiety in the condensate is unstable and is decomposed. Although N-acylamino acid amides represented by N-lauroyl-L-glutamic acid α,γ-di-n-butylamide are able to gel or solidify many organic media in small adding amount and strength of the resulting gel is high as well, their gelling ability to lower alcohol such as methanol is poor and they do not always have a satisfactory gelling ability.
In order to improve the disadvantages as mentioned above, development of gelling agents or solidifying agents for organic media has been briskly carried out in recent years. Examples thereof are cyclohexane tricarboxamide (Patent Document 6: JP-A-10-273477), bis(acylamino)cyclohexane derivatives (Patent Document 7: JP-A-10-237034), oligopeptide alkylamide derivatives (Patent Document 8: JP-A-10-245396; Patent Document 9: JP-A-10-226614), dialkylurea derivatives prepared by the reaction of diaminocyclohexane with alkyl isocyanate (Patent Document 10: JP-A-8-231942), cyclic dipeptides (Patent Document 11: JP-A-7-247474); Patent Document 12: JP-A-7-247473), Nα-alkyl or alkenylcarbamoyl-Nω-acylamino acid ester compounds (Patent Document 13: JP-A-2000-256303), etc. They are able to gel or solidify various kinds of liquid organic media in small additional amount, strength of the resulting gel is strong and stability around the ambient temperature is good as well. On the other hand however, gelling ability is greatly affected by steric configuration of the compound whereby synthesis and separation of the material having a specific steric configuration are difficult, availability of the material is difficult or, in the manufacture, there are many reaction steps and the process is complicated whereby there is a problem in productivity.
Further, Nα-alkyl or alkenylcarbamoyl-Nω-acylamino acid ester compounds (Patent Document 13: JP-A-2000-256303) are disclosed as gelling agents or solidifying agents for varieties of organic media such as lower alcohol, chlorine-type solvents or hydrocarbon oils. Even by them however, there is a variation in the gelling ability depending upon the type of the organic medium such as that, as compared with hydrocarbon oil, the gelling ability for lower alcohol or chlorine-type solvent is low.